Simple letters would be sent round most nations, on billboards and the like.
“The City-state of Al Jabrid is seeking trading folk to set up shop or make deals with, as well as the formation of a continent-spanning route for trade caravans. Particularly anyone from the neighboring towns who are interested across our way. There are many festivals and feasts in store for the coming days, and we seek to bring back many of the traditions and storefronts missing from home. Please contact Os or Aegnern for inquiries.”
“The City-state of Al Jabrid is seeking trading folk to set up shop or make deals with, as well as the formation of a continent-spanning route for trade caravans. Particularly anyone from the neighboring towns who are interested across our way. There are many festivals and feasts in store for the coming days, and we seek to bring back many of the traditions and storefronts missing from home. Please contact Os or Aegnern for inquiries.”